The present application relates generally to the field of drive systems for lawn tractors. More specifically, the present application relates to a drive system including an internal combustion engine and secondary drive such as an electric motor.
Lawn tractors are generally driven by an internal combustion engine, with the engine being used to power both the wheels to propel the vehicle and to power an accessory, such as cutting blades via a power take-off device. While driving the wheels can be a lower power draw, operating the accessory can be a much higher power draw. Internal combustion engines are generally most efficient when operated in a narrow power band. It can therefore be advantageous to supplement or replace an internal combustion engine with a secondary power source, such as electric motor.
Electric lawn tractors use batteries to power both deck motors (for driving the cutting blades) and wheel motors to drive the wheels. However, utilizing only battery power can be limiting. High power draw of deck motors can quickly discharge batteries. Once the batteries are drained, there is an extensive re-charge period. The power draw can be reduced to extend cutting times by reducing blade speed, utilizing smaller diameter decks, and utilizing lower lift blades. While these solutions reduce power draw, they can also negatively affect the cutting performance of the lawn tractor.